The proposed project is a four year family study of the familial aggregation of suicide and suicidal behavior among the families of adolescents. The rates of suicide, suicidal behavior, Axis I and Axis II psychiatric disorders will be compared among the relatives of three groups: 75 adolescent suicide completers ("completers"), 75 hospitalized adolescents who have made at least one suicide attempt ("attempters), and 75 psychiatrically hospitalized never- suicidal adolescents ("controls"). The two hospitalized groups will be frequency-matched on age, race, sex, and broad-band psychiatric diagnosis to the completers. Lifetime history of psychiatric disorder (Axis I and II) and tendency to impulsive violence will be assessed in the probands and by direct interview (Family Study) in the first-degree relatives and designated grandparents, aunts, and uncles of the probands. The remainder of the second-degree relatives and those first-degree relatives unavailable for direct interview will be assessed indirectly by the Family History Method. The specific aims of the study are to test the following hypotheses: (1) The families of completers will show higher rates of suicide than the families of attempters, but both the relatives of completers and attempters will show higher rates of suicide and suicidal behavior than the relatives of controls: (2) The families of completers and attempters will show similar rates of Axis I disorders, but will show higher rates and earlier ages of onset of bipolar disorder and substance abuse, when compared with families of controls: (3) The families of completers and attempters will show higher prevalence of antisocial, borderline, and histrionic personality disorders, and a greater tendency to impulsiveviolence and sensation seeking when compared with families of controls; (4) Among the families of completers and attempters, higher rates of suicide and suicidal behavior will be observed among the families of those probands: (a) with affective disorder, (b) who have made high intent attempts/completions, and (c) who have made violent attempts/completions. This is a revision of grant 1 R01 MH43366-01.